PL/SQL constraint 求教？ - 未名空间MITBBS历史存档

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PL/SQL constraint 求教？

PL/SQL constraint 求教？# Database - 数据库

f*e2003-04-20 07:04

1 楼

现在我有type point and type line, table polygons(多边形)如下：
create or replace type Point as object(
X float,
Y float
);
/
create or replace type Line as object(
SP point, -- start point
EP point -- end point
);
/
create or replace type LineTableType as
table of Line;
/
create table Polygons(
PID integer,
Lines LineTableType
)
nested table Lines store as LinesTable;
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n*a2003-04-20 07:04

2 楼

Check constraint can only be enforced on a table.
And you can define constraints on the leaf-level scalar attributes of a column
object.
However, in your case, Polygons.Lines is a table collection of objects.
I don't think you declare a simple check constraint.
Use trigger to iterate each member of Polygons.Lines and check for error
conditions
create or replace trigger trig_polygons
after insert or update on Polygons
for each row
begin
for i in 1..:new.Lines.count loop
if :new.Lines(i).SP.

【在 f***e 的大作中提到】

: 现在我有type point and type line, table polygons(多边形)如下：
: create or replace type Point as object(
: X float,
: Y float
: );
: /
: create or replace type Line as object(
: SP point, -- start point
: EP point -- end point
: );

f*e2003-04-20 07:04

3 楼

thank you so much!

column

【在 n********a 的大作中提到】

: Check constraint can only be enforced on a table.
: And you can define constraints on the leaf-level scalar attributes of a column
: object.
: However, in your case, Polygons.Lines is a table collection of objects.
: I don't think you declare a simple check constraint.
: Use trigger to iterate each member of Polygons.Lines and check for error
: conditions
: create or replace trigger trig_polygons
: after insert or update on Polygons
: for each row